1. Field of the Invention
The present invention relates to a plasma display panel (PDP), and more particularly, to coupling and grounding structures of a circuit board in a plasma display device.
2. Description of the Related Art
In general, a plasma display panel (PDP) displays images using gas discharge operations, and has excellent display characteristics such as display capacitry, brightness, contrast, residual image, and viewing angle. Thus, the PDP can substitute for a cathode ray tube (CRT). In the PDP, a discharge occurs in a gas between electrodes due to a direct current (DC) or alternating current (AC) being applied to the electrodes, and phosphors are excited by ultraviolet rays caused by the discharge operation and emit lights.
The PDP can be classified into an AC type and a DC type according to a discharge mechanism thereof. The DC type PDP includes the electrodes that are directly exposed in the gas layer filled in discharge cells, and voltage applied to the electrodes is applied to the discharge gas layer. In addition, in the AC type PDP, electrodes are separated by both the discharge gas layer and a dielectric layer, the electrodes do not absorb charged particles generated in the discharge operation to form wall charges, and the discharge operation is performed using the wall charge.
In the general PDP, the panel is attached to a chassis base while interposing a heat-radiation sheet having thermal conductivity. In addition, a circuit board, on which a plurality of electronic elements are mounted, is coupled to a boss that is formed on the chassis base. The circuit board is coupled to the boss using bolts by arranging a plurality of coupling holes that are formed on the circuit board with the boss. Therefore, the bolts must be coupled tightly.
I have determined that in such a case, the circuit board may be damaged or distorted due to the bolts being over tightened. Additionally, the bolts may be loosened during thermal distortion or vibration of the circuit board. Accordingly, the grounding is performed poorly. Also, if the grounding of the circuit board is performed poorly, current and voltage noises cannot be controlled effectively, and electromagnetic interference (EMI) characteristics will be lowered.